New Brakes and they started to squeal when stopping

I installed new rotors and pads. All was good for a week or 2 and they are now starting to squeal when I stop. Usually happens the first few min. I did put silicone (light coat with my finger) on the back of the pads. They didnt have shims on the new pads. I was thinking about pulling them back apart and regreasing the pads and also the stainless steel clips (didnt to this the first time). Anyone have this issue? Should I have used the other kind of silicone that hardens and acts like a glue?

Any advice and tips would be appreciated.

Wagner ThermoQuiets (not so much) pads and rotors.

Thanks again.